Refrigerating apparatus



May 24, 1956 J. J. o-coNNE| ETAL 3,252,292

REFRI GERATING APPARATUS May 24, 1966 J. ocoNNELL ETAL 3,252,292A

REFRIGERATING APPARATUS Filed Feb. lO, 1964 4 Sheets-Sheet 2 i May 24, 1966 J. .l` O'CONNELL ETAL 3,252,292

REFRIGERATING APPARATUS 4 Sheets-Sheet 3 Filed Feb. l0, 1964 F ig. 4

INVENTORS John J. O'Gonnel/ Leonard J. Mann The/r Aforney u May 24, 1966 .1. J. ocoNNELL ETAL 3,252,292

REFRIGERATING APPARATUS Filed Feb. l0, 1964 4 Sheets-Sheet 4 n J OINGVENTI o n ann Fly. 7 BY/ eonard J. Man

The/'r Afforney United States Patent 3,252,292 REFRIGERAT NG APPARATUS John J. OConnell and Leonard J. Mann, Dayton, Ohio, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed Feb. 10, 1964, Ser. No. 343,736 2 Claims. (Cl. 62-77) This invention pertains to refrigerating apparatus and more particularly to a refrigerator having below and above freezing compartments separately cooled by separate air circuitscooled by a single evaporator.

The growing popularity of frost free refrigerator compartments makes it desirable to market a greater variety of sizes of refrigerators having this and other desirable features. It is therefore an object of this invention `to provide a large capacity, compact, economical, low c'ost refrigerator which is inexpensive to manufacture and maintain, having the desired below and above freezing temperatures in separate compartments which will not accumulate frost in any of the storage compartments.

It is another object of this invention to provide a compact, removable refrigerating system and a convenient inexpensive arrangement including a removable wall section of minimum size for readily installing and removing such a system in a foam insulated refrigerator Cabinet.

It is another object of this invention to provide an improved compact, eiiicient air circulating system for a two-compartment refrigerator cabinet.

It is another object of this invention to provide a simple single compact evaporator in a two-compartment refrigerator which minimizes the obstruction to air iiow due to frost accumulation on the evaporator surfaces.

It is another object of this invention to provide a well arrangement in a form insulated refrigerator cabinet by which the thermosensitive element of the control system may be readily inserted and located in the desiredplace and readily removed whenever desired.

It is another object of this invention to provide an improved arrangement for defrosting an evaporator and environmental parts subject to frosting.

These and other objects are attained in the form shown in the drawings Iin which the lower below freezing compartment is provided with a raised rear portion over the compressor and condenser above which there is motilited`a single vertically finned evaporator having widely spaced fins at one end and closely spaced tins for the remainder thereof. An insulated vertical partition wall separates the evaporator from the below freezing compartment immediately in front of it. The below freezing compartment is cooled by air which is drawn under the bottom of the partition wall and upwardly through the closely finned portion of the evaporator and discharged back into the compartment by a propeller type fan located in an aperture in the partition wall. The rear insulated wall of the below freezing compartment is provided with an opening normally closed by a narrow re- -movable section which is slightly higher than the height of the evaporator and slightly wider thanthe thickness thereof. The compressor and condenser mounted beneath the raised portion are connected by supply and return conduits which extend through the opening in the rear wall and connect to the opposite end of the evaporator through two looped portions located at the opposite ends of the evaporator. This arrangement provides sufiicient flexibility in the connections that the evaporator can be readily inserted through this opening and mounted at the back of the below freezing compartment. It may likewise be readily removed along with the removal of the compressor, and the condenser for examination and repair in the event of any failure.

Patented May 24, 1966 A duct extends diagonally upwardly from the zone irnmediately above the widely spaced fin portion and has a first discharge outlet behind the meat-keeping container in the lower right side, and a second discharge outlet in the top central portion of the above .freezing compartment. On the lower left side of the above freezing compartment is a centrifugal fan which discharges through an expanding duct diagonally downward to a discharge outlet located behind the lower portion of the widely spaced finned evaporator portion. A switch mounted in the top portion of the above freezing compartment has a thermosensitive element extending Idownwardly through a well or tube in `the foam insulation extending to the top of the below freezing compartment so as to make the switch responsive to the temperature of the air at the top of the below freezing compartment. The centrifugal fan located in the lower left part of the above freezing compartment is cycled in response to the temperature of the adjustable thermostatic switch mounted in the top portion of the above freezing compartment, and having a thermosensitive element located above the second discharge outlet so as to be responsive to the temperature of the above freezing compartment. A timer periodically defrosts both sections of the evaporator through a serpentine electric heater lodged in the fins of the evaporator having a proportionately greater portion in heat transfer relation with the widely spaced iin portion of the evaporator which accumulates lthe most frost. The drain surfaces as well as the partition wall are provided with heaters energized coincidentally with the energization of the defrost heater for melting any frost or ice accumulating on the drain surfaces or the partition wall. The drain is provided with a removable cover for easy cleaning and is provided with a simple removable trap in the machinery compartment.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment ofthe present invention is clearly shown.

In the drawings:

FIGURE l is a front view, with the doors removed, of a 2-compartment household refrigerator embodying one form of my invention;

FIGURE 2 is an irregular vertical section taken substantially along the lines 2 2 of FIGURE 1;

FIGURE 3 is a fragmentary sectional view taken substantially along the lines 3 3 of FIGURE l;

FIGURE 4 is an enlarged sectional view corresponding to the bottom of FIGURE 3 showing the heaters for the drain surface and the partition Wall;

FIGURE 5 is a sectional view taken along the lines 5-5 of FIGURES l and 2;

FIGURE 6 is a front view of the below freezing cornpartment showing the cycle evaporator in position fOr removal through the opening provided in the rear wall; and

FIGURE 7 is a wiring diagram.

Referring now more particularly to FIGURES l and 2, there is shown a foam insulated household refrigerator cabinet 20, having an upper above freezing compartment 22, and a lower below freezing compartment 24, beneath which is a machinery compartment 26 having separating the latter compartments a low front insulated wall portion 28 and a stepped up rear wall portion 30, which is raised substantially above the front portion 28 to provide adequate space beneath for the sealed motor compressor unit 32 and the sheet-type condenser 34. The rear insulated Wall 36, behind the below freezing compartment 24, is provided with a narrow vertical removable portion 38 covered by a metal cover 40 beneath the lower edge of which extends the capillary tube supply conduit 42 connecting the condenser 34 with the single evaporator 44 and a suction conduit 46 connecting the outlet of the evaporator with the suction inlet of the compressor 32. On the left end of evaporator 44 the conduits 42 and 46 are provided with a vertical loop portion 48 providing exibility `of the conduits 46 and 42 to permit removal of the evaporator 44 through the opening provided when the removable portions 38 and 40 are removed.

This removal is clearly illustrated in FIGURE 6. The entire refrigerating system may be removed by removing the compressor 32 and the condenser 34 through the opening in the back of the machinery compartment 26 along with the evaporator 34, so that the refrigerating system is kept intact and may be removed for examination or sent away for repair. The refrigerating system is readily inserted by inserting the right end through the opening provided by the removal of the section 38, and passing the entire evaporator through this opening and then placing it above the rear of the raised portion 30. The refrigerant conduits 42 and 46 extend from the condenser 34 and the compressor 32 through the opening at the bottom of the section 38 to the looped portion 48 and connecting respectively to the inlet connection 50 and to the top of a vertically mounted accumulator 52 having its bottom portion connected to the evaporator outlet 54. The evaporator 44 has horizontal serpentine tubing provided with Widely spaced vertical ns 56 on the right side of the vertical partition wall `58 and a closely finned section 60 on the left side of the vertical partition wall 58. An insulated partition wall y62 is provided in front of the evaporator 44 and substantially extends entirely across the rear of the below freezing compartment 24. It includes an insulating sheet 64 which is faced with a metal sheet 66 having a bottom edge 68 turned readwardly at an' angle beneath the lower beveled bottom portion of the insulating sheet 64. Behind the upper portion of the sheet portion 64 is provided a horizontal insulated structure 70 spaced above the evaporator 44 having vertical partition wall portions 711 and 73 extending downwardly to the opposite ends of the evaporator 44 and an intermediate vertical wall portion 76 extending downwardly to the partition Iwall 58. The insulating sheet 64 and the metal facing sheet 66 are terminated short of the step portion 30 in front of the closely spaced n portion 60 to provide an air entrance beneath the bottom edge 68 through which air from the compartment 24 enters the space beneath the closely finned part 6) of the evaporator 44. A propeller-type fan 72 is rotatably mounted in an aperture 74 in the sheet 64 and the metal sheet 66 at a level higher than the evaporator 44 between the wall portion 71 and '76 for drawing the air from the compartment 24 beneath the bottom beveled edge 68 for drawing the air upwardly through the closely spaced n portion 60 and discharging the air forwardly in the upper portion of the below freezing compartment 24. It is driven by an electric motor 69.

A fan scroll 78 located on the lower left-hand corner of the back wall of the above freezing compartment 22, surrounds a centrifugal fan 80 driven by an electric motor 82 for drawing air from the above freezing compartment, yand discharging the air through an expanding shroud84 to a duct 86 extending through the rear wall 36 diagonally downwardly to a discharge outlet 88 in the rear wall 36, behind the bottom of the widely spaced finned portion .56, of the evaporater 44. This air flows upwardly through the widely spaced fin portion 56 to the air entrance 90 above the evaporator 44. The entrance 90 leads to a second air duct 92 in the rear wall 36 which extends diagonally lupwardly and'has a small rst air discharge opening 94 discharging through the rear Wall into the above freezing compartment directly behind the meatkeeping container 96. This air discharge 94 keeps the meat-keeping container at .a temperature of about 30 F.

which is sufliciently cold to keep meats for a substantial period of time and in satisfactory condition without freezing.

The second air duct 92 extends diagonally upwardly within the backwall of the cabinet to the upper centrally located discharge outlet 123 located a fewinches below the top wall of the refrigerator cabinet, The fan 80 is preferably located directly behind the high humidity container 98 on the left side of the above freezing compartment 22, directly above the insulating wall 121 which separates the below freezing compartment 24 from the above freezing compartment 22. The air at a temperature of about 35 F. flows through the above freezing compartment 22 and around the container 98 to keep this container at a suitable temperature such as 35 F. for the moist storage of fruits and vegetables. On the rear wall of the compartment 22 between the outlet 123 and the top wall 126 is a thermosensitive element or capillary tube 125 -which is operably connected to the adjustable thermostatic switch 1-27 mounted on the right side of the discharge outlet 12-3. This switch 127 is connected in series with the fan motor 82, as indicated in FIGURE 7, for the purpose of maintaining the temperature in the compartment 22 at about 35 F., and the ternperature in the meat-keeping container 96 at a temperature of about 30 F.

On the opposite side of the upper discharge opening 123 is a second adjustable thermostatic switch 129 which has a thermosensitive element extending down through a tube or well 131 in the insulation of the rear Wall 36 to a terminal point 1313 mounted on the top wall 1211 of the below freezing compartment 24 as shown in FIG- URES 1 and 2. This thermosensitive element is in the form of a capillary tube having a closed end in the portion 133 and connecting at its upper end to a fluid motor within the switch 129. An illustration of such a switch is shown in Pat. No. 2,906,132 issued September 29, 1959.

For the purpose of defrosting the evaporator 44, there is provided a serpentine sheathed electric heater 13f5 having, as shown in FIGURE 6, one lower loop 137 extending across both the widely spaced fins 56 and the closely spaced ns 60 and having two short upper loops 1239 extending into heat transfer relation only with the widely spaced fins S6 so as to provide more heat for this portion of the evaporator since a greater amount of frost collects upon it. Upon the backside of the evaporator are provided several loops 141 of the heater 135 which extend across both the closely spaced fins 60 and the widely spaced tins 56. For the purpose of collec-ting the water during defrosting, the raised portiontl is provided with an inclined drain trough 143 extending downwardly from the left to the right to a point opposite the drain 145 in the rear right corner. This drain is provided with a removable cover 147 for access to the drain for cleaning purposes, and for shielding the drain from the circulating air. The drain is connected to tubing 149 extending through the machinery compartment 26 to la removable diagonal drain and seal member 151 having a normally closed end portion 153 which normally has a at looped shape at the end so as to prevent flow of air there through. It, however, will allow the ow of water into the collecting drain pan 155 located in the front part of the machinery compartment 26 where it is in the flow of air which is circulated by the condenser fan 157 driven by the fan motor 159. The drain 143 is provided with a drain heater 161 in the form of a loop extending along the bottom having a second portion 163 (see FIG. 7) extending to the drain 145, and having a third portion 165 extending laterally between the bottom edge 68 of the sheet metal face 66 and the beveled bottom edge of the insulating sheet 64 of the dividing wall 62.

As illustrated -in FIGURE 7, a timer motor 16-7 is connected across the supply conductors L-l and L-2 and at intervals of once or twice a dayoperates the dual switches 169 and 171 from the position shown in FIGURE 7 to a position in which the switch 171 is opened and the switch 169 is closed. When the switch 171 .is opened, the flan motors 76, 72, and 1159, as well as the motor compressor unit 32, are de-energized. The closing of t-he switch 169 energizes the defrost heater `135 including the portions 137, 139, and 141. Connected in parallel with the de- Ifrost heater are the two portions of the drain heater 134 and 163, and the heater 165 upon the bottom of the member 66. The drain heaters insure that any ice in the drainage system will be melted before the defrost water melted from the evaporator 44 reaches the different parts of the draining system. The heater 165 assures that any frost or ice collecting upon the partition wall 62 will be melted during the defrost period. The fan motors 78 and S2 may also be stopped whenever the doors 173 and 175 are opened through the opening of the switches 177 and 179 which are operated respectively by the doors 173 and 175.

The motor compressor unit along with the fan 157 and its motor 159 and the condenser 34 may be removed through the rear opening of the machinery compartment 26. The evaporator 44 may be removed by removing the section 38 of insulation and the cover 40 and withdrawing the evaporator through the opening provided by this removal as illustrated in FIGURE 6 by moving the left end of the evaporator 44 first throug-h the opening and then withdrawing the remainder through the opening until it is free of the cabinets. The refrigerating system is capable of maintaining the compartment 24 at temperatures between 6 and 12 F. Normal operation is 0 E. While the above freezing compartment 22 is capable of maintaining a temperature of about F. therein, with the exception of the meat-keeping container which is maintained at about 30 F. The timer motor 167 provides defrost periods once or twice a day automatically without any attention. The foam insulation is sufficiently eicient that only thin insulated walls are required. 'The use of a single finned evaporator to cool both compartments makes the cost of manufacture relatively low, while the arrangement of completely separate air circulating systems between the two compartments and the two sections of the evaporator provide desirable temperature and humidity conditions in both compartments at a relatively low cost. The use of the diagonal duct arrangements makes the arrangement compact and minimizes the thickness required for the rear wall.

While the embodiment of the .present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. A method of assembling a refrigerator including insulating means enclosing a compartment to be cooled and having an opening in a rear wall thereof, a se-aled refrigerating system comprising refrigerant liquefying means provided with iiexible refrigerant conduits connecting with a refrigerant evaporating means having a height and thickness smaller than said opening bu-t a length which is substantially greater than any dimension of said opening, comprisingt-he steps of inserting the evaporator means from the outside with one end of the evaporator irst passing through the opening into the compartment, turning the evaporator means about and locating the evaporator means in the desired transverse position within said compartment, and bending the liexible conduits to the extent necessary to move .the evaporator means to the desired position and mounting it in the desired position.

2. A refrigerator including insulating means enclosing a below freezing compartment and an above freezing compartment, said insulating means including an insulated rear wall for said below freezing compartment, a generally rectangular refrigerant evaporating means having a predetermined height and width and thickness located within said below freezing compartment and extending transversely in front of the rear wall thereof with its longest side extending from a location adjacent one side of said rear wall to a location adjacent the other side thereof, said insulated rear wall adjacent one side of said below freezing compartment being provided with an opening greater in height and width than the front to rear and top to bottom dimensions of said evaporating means but substantially less than the longest side of said evapo- `rating means, a refrigerant liquefying means located outside said insulating means, .exible hermetically sealed refrigerant conduit means extending through said opening in said insulated rear wall operatively and hermetically connecting said evaporating and liquefying means, and a removable insulated closure for said opening in said rear wall.

References Cited by the Examiner UNITED STATES PATENTS 1,882,752 1.0/ 1932 lBlood 62-449 X 1,949,663 3/1934 Sellman 62-448 2,387,465 10/1945 Peltier 6'2-449 2,392,727 `1/194-6 Dailey 62-449 2,496,492 l2/1950 Prosek 6'2-449 2,798,367 7/19517 Earle 62-449 X 2,912,834 11/ 1959 Mann 612-276 2,982,115 5/ 1961 Wurtz et al 62-419 3,005,321 11/ 1961 Devery 612-186 3,025,683 3/1962 Baker et al 6'2-419 3,048,985 8/19612 Long 6-2-186 3,120,111 2/ 1964 Simmons 6t2276 `ROBERT A. OtLEARY, Primary Examiner.

LLOYD L. KING, Examiner. 

1. A METHOD OF ASSEMBLING A REFRIGERATOR INCLUDING INSULATING MEANS ENCLOSING A COMPARTMENT TO BE COOLED AND HAVING AN OPENING IN A REAR WALL THEREOF, A SEALED REFRIGERATING SYSTEM COMPRISING REFRIGERANT LIQUEFYING MEANS PROVIDED WITH FLEXIBLE REFRIGERANT CONDUITS CONNECTING WITH A REFRIGERANT EVAPORATING MEANS HAVING A HEIGHT AND THICKNESS SMALLER THAN SAID OPENING BUT A LENGTH WHICH IS SUBSTANTIALLY GREATER THAN ANY DIMENSION OF SAID OPENING, COMPRISING THE STEPS OF INSERTING THE EVAPORATOR MEANS FROM THE OUTSIDE WITH ONE END OF THE EVAPORATOR FIRST PASSING THROUGH THE OPENING INTO THE COMPARTMENT, TURNING THE EVAPORATOR MEANS ABOUT
 90. AND LOCATING THE EVAPORATOR MEANS IN THE DESIRED TRANSVERSE POSITION WITH- 